1. Field of the Invention
The present invention relates to a rotary compressor for compressing various types of fluids, for use as pumps or superchargers for internal combustion engines.
2. Description of the Related Art
Such a rotary compressor hitherto known comprises, as described in, e.g., Japanese Utility Model Registration Laid-open Publication No. 59-181284, a casing having an inflow port and an outflow port for a fluid which open on its inner surface, a cylindrical outer rotor rotatably housed in the casing, a cylindrical inner rotor rotatably supported at an eccentric position within the outer rotor, and a plurality of vanes slidably attached, in the radial direction, to grooves formed in the outer peripheral surface of the inner rotor, wherein a fluid is sucked through the inflow port of the casing into a space between the outer rotor and the inner rotor partitioned by the vanes, the fluid being discharged through the outflow port of the casing.
However, due to the structure of the conventional rotary compressor in which the tips of the vanes whirl in contact with the inner peripheral surface of the outer rotor, the loss attributable to mechanical friction is significant, making difficult the use in high-speed rotations, as in the case of use as, e.g., an automobile supercharger.